Electrical connector



Dec. 2, 1958 L. K. YEISER ELECTRICAL CONNECTOR Filed Dec. 14, 1955 IN VEN TOR. Igon W Ymser United ELECTRICAL CONNECTOR Leon K. Yeiser, Lebanon, Pa., assignor to Aircraft-Marine Products, Inc., Harrisburg, Pa.

A highly specialized use of wire termination is involved in connecting a braided shield covering a cable to a grounding means. More particularly, in the application of a shielded cable to a magneto or other fitting, it is necessary to provide a grounding means by connecting the shielding braid to the fitting. Some of the connectors presently is use are crimped or pressure forged to the shielding braid. One of the defects inherent in prior devices includes a relaxation of the connection after a period of use, specially under vibrational stresses, such as are set up in aircraft. Since the material backing up the crimp is usually flexible, there is a gradual relaxation of the structure after the crimp is made. This is particularly undesirable in the electrical system of aircraft, since a relaxed connection may produce intermittent contact which not only results in a poor connection but also causes static in the radio system.

Thus, it is an object of this invention to provide an electrical connector for use on shielded cable.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction With the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

Figure 1 is an exploded view of a shielded wire and a connector embodying principles of this invention;

Figure 2 is a plan view on a reduced scale of the device shown in Figure 1, fitted to a conductor;

I Figure 3 is a longitudinal cross-sectional view taken through the assembly showing on a larger scale the connector crimped onto the conductor; and

Figure 4 shows the device on a reduced scale and secured to a magneto fitting.

As shown in the drawing a shielded cable designated C consists of an inner conductive element 10, surrounded by resilient insulation 12, which in turn is surrounded by metallic braid 14, which in turn is surrounded by insulation 16.

The connector, generally designated 20 (see Figure 2), is employed for securing the metallic braid 14 in electrically conductive relationship with another member, for example, a magneto fitting F, as shown in Figure 4.

In the preferred embodiment shown, the connector is made in two sections, although other variations are readily apparent. As shown in Figure l, a first section consists of a ferrule 30 having an inside diameter slightly larger than the outside diameter of the cable. One end of ferrule 30 is flared outwardly, as at 32, to permit Patent the braided portion of the cable to be inserted into the ferrule.

The other section of the connector includes an inner ferrule 34 and a concentric outer flange 36 spaced therefrom. A rim 38 connects one end of ferrule 34 integrally with the corresponding end of ferrule 36. As shown in the drawings, rim 38 is set at an angle to the longitudinal axes of the cable so that it will accommodate the particular fitting F (see Figure 4). A cut out portion 40 is provided in the rim of flange 36 .to facilitate collapsing of the ferrule.

When it is desired to secure the connector to the conductor, insulation 16 is first stripped back to a point that uncovers a section of braid 14. Next, outer ferrule 30 is slipped over the cable and moved rearwardly over insulation 16 so that the exposed portion of the braid has been passed through ferrule 30. Then ferrule 34 is slipped under braid 14 so that the ferrule is positioned between braid 14 and insulation 12. One end of ferrule 42 is set at an angle to the longitudinal axis of the connector (see Figures 2 and 3) to provide for easier insertion of the ferrule under braid 14.

When ferrule 34 is inserted Within the braid as far as possible, the end of the braid will be juxtaposed adjacent to rim 38, and may even be somewhat turned back upon itself as shown in Figure 3. Ferrule 34 underlying the braid acts as a rigid support means for the braid. Ferrule 30 is then slid as far as it will go toward the end of the braid and into contact with rim 38.

The connector is permanently deformed by suitable means, such as a tool of the type set forth in patent application Serial No. 553,072, filed in the name of Leon Yeiser on December 14, 1955, now Patent No. 2,824,472.

The deformation on the connector occurs in a radial and also a longitudinal direction. Radial deformation of ferrule 30 serves to provide a tight engagement be tween the outer ferrule and the inner ferrule. Thus, the inner ferrule acts as a support means or backs up the outer ferrule. This pinches braid 14 between the two ferrules to provide a positive connection between the braid and the connector. Without the inner ferrule, the outer ferrule would be deformed upon the braid which would be supported by resilient insulation. This resiliency of the insulation provides a certain amount of flexibility between the braid and the connector which, during the life of the connection, may operate to destroy or impair this connection. However, by the use of the rigid support means the braid is firmly grasped and held between the ferrules throughout the life of the connector.

As a further means of securing the braid to the connector, the connector is deformed longitudinally. By controlled deformation, inner ferrule 34 is collapsed radially at 40 (Figure 3) to encompass securely the insulation 12. Relaxation of insulation 12 is no longer of any moment, since the connection does not rely on the insulation for support, but rather is backed up by ferrule 34. Ferrule 30 is bulged outwardly at 43 to lock with curl 44 formed in flange 36. This provides a keying action which secures these ferrules together. The braid 14 as shown in Figure 3 may be rolled back on itself, as at 46, to provide extra thicknesses of braid Within bulge 43. Thus, the braid is keyed into the space formed by bulge 43. Bulge 43, the extra thickness of braid 46 and curl 44 all cooperate to secure the connection against stresses which may be exerted longitudinally.

The deformation of the connection is designed to shape the outer end 38 at an angle which is commensurate with the surface angle of the fitting. Thus, as shown in Figure 4, surface 38 mates with fitting F. A lock nut L surrounds the connection and threads onto the fitting to secure the connector to the fitting. The connector aaeaooa '2 g thus grasps the shielded braid 14 and acts as a conductor between the braid and fitting P, so that the fitting serves to ground the braid.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. An electrical connection betweenja connector and theshielding of a shielded cable including: an inner ferrule, and an outer ferrule, with the shielding gripped therebetween, a retroverted flange on one end of the innor ferrule surrounding one end of the outer ferrule and also surrounding one end of the shielding, a bulge at said one end ofthe, outer ferrule adjacent to the retroverted flange and defining a space between the outer and inner ferrules, said shielding extending outwardly into the space formed by the bulge being keyed therein and means for locking the retrov'erted flange to the outer ferrule- I 2. The device of claim 1 wherein the means for lockthe flange to the outer ferrule comprises the rim of the flange, said rim having a lesser diameter than the bulged portion of the outer ferrule, and said rim disposed between the bulged portion and the other end of the outer ferrule.

3. The device of claim 1 wherein the junction of the inner ferrule and the flange has a lesser diameter than the inner ferrule, whereby the inner ferrule and flange are secured to the cable.

References Cited in the file of this patent UNITED STATES PATENTS 1,188,056 Faile June 20, 1916 2,536,003 Dupre Dec. 26, 1950 2,694,183 Elden et a1 Nov. 9, 1954 FOREIGN PATENTS 102,137 Great Britain Nov. 13, 1916 OTHER REFERENCES Publication I: Grounding Shielded Cables (Manzi et al.), published in Electrical World December 1942, pages 128130 (all pages relied on). (Copy in Scientific Library and Div. 69, Class 174-35C.) 

